This invention relates to automatic sprinkler systems and in particular to a mechanism which facilitates adding sprinkler heads to an existing automatic control system.
Automatic control systems for timing and sequencing the operation of multiple lawn sprinklers are well known. The simplest of systems contains an electric timer controlling a solenoid valve in the water supply line to the sprinkler heads. By setting the actuation time, the sprinklers are programmed to operate for a predetermined duration at a predetermined time each day. More complex systems operate the sprinkler heads in subsets. This prevents the simultaneous operation of all sprinklers from overloading the water supply capacity which would result in reduced pressure and inadequate lawn coverage. To attain actuation of all sprinklers the subsets are sequenced in and out of operation.
As electronic digital controllers became readily available, they were applied to sprinkler system control. An example of this type of application can be found in U.S. Pat. No. 4,190,884 to Alvaro Medina, issued Feb. 26, 1980. The digital control technology provided exceptional flexibility to the control function. Operation of individual sprinkler heads could be independently programmed in accordance with the requirements of the flora surrounding that sprinkler. In addition, programming flexibility enabled automatic seasonal adjustment of spray duration and automatic program adjustment by either humidity or soil moisture measurement. One of the major benefits of this programming flexibility is the capability to tailor a particular system for varieties of landscaping. Landscaping is generally made to conform to the utilitarian aspects of commercial or residential buildings. Often these utilitarian aspects are modified during the useful life of the building. Rooms or structures may be added or vehicle parking space may be expanded. These modifications can have considerable impact on landscaping with resulting changes to the sprinkler system which can be accommodated by a flexible programming system.
Notwithstanding past improvements in sprinkler systems, a major disadvantage remains. Programming flexibility is limited by the number and location of originally installed sprinkler heads. Landscaping modifications requiring additional sprinkler heads necessitate major piping and wiring changes to incorporate the new sprinkers in the program.